Electropneumatically operated window



A. H. rAsHJlAN E1' Al. 2,067,106 ELECTRONEUMATICALLY OPRATED WINDOW Filed sept. 24, 1954 2 sheets-sheet 1 Jan. 5 1937.

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WITN SSES Jan. 5, 1937. A. H. TAsHJlAN'Er Al. 2,067,106

ELECTROPNEUMATIGALLY OPERATED WINDOW Filed Sept. 24, 1954 2 Sheets-Sheet 2 Remon comm WIT E 5 a l i Y 'ATTORNE'Y Patented Jan. 5, 1937 NETEDI S TAT ES PATE NT OFFI CE i ELECTROPNEUMATICALLY" OPERATED WINDOW Armen H. Tashjian and Dean H. Holden, Cleveland, Ohio,

assgnors, by mesne assignments,

'rms inventiony relates to improvements in pneumatically operated double hung windows, and its objects are as follows:-

First, to provide an electro-pneumaticall-y operated double hung window' of simple and inexpensive construction, operable by the turn of a local or remote switch, irrespective of size or weight of `sash or location of window.

Second, to provide an electro-pneumatic double hung window with concealed lock, inaccessible to outside prowlers. i

Third, to provide an electro-pneumatic double hung window either sash of which can be locked automatically at any desired position.

Fourth, to provide a simple, compact and inexpensive mechanism for raising or lowering either sash of a window or any group of` windows, mechanically using compressed air or other pressure uid for power and electrical means for automatically controlling the same.

Fifth, to lower either sash by gravity yet with retarded acceleration on va cushion of air of accurate amount, said amount being controlled automatically by the weight of the sash to be 5 lowered.

Sixth, to prevent the withdrawal of sash lock plungers until air in sufcient amount has been introduced into sash cylinders to balance the weight or gravity of the sash before lock plunguo ers are automatically withdrawn.

Seventh, to operate either sash of a window or group of windows either by local control, as by switches emplaced on the window frames or by a remote control situated elsewhere in the :x3 room or at some more distant point.

In the drawingsz Figure 1 is a partially sectional and front elevational view of a window constructed in accordance with the invention.

if) Figure `2 is a vertical section taken on the line 2-2 of Figure 1, particularly illustrating the sash cylinders and the stationary pistons.

Figure 3 is an end view of the lower sash as seen on the line 3-3 of Figure 1, particularly i5 illustrating the lockstrip i'lxedly carried thereby.

Figure 4 is a cross section vtaken on the line 4--4 of Figure 1, particularly illustrating the meeting rails of sashes 'and their weather stripping. i

Figure 5 is a sectional view of the sash cylinders and piston at the right of Figure 1, illustrating thedetails on a slightly larger scale.

Figure 6 is a vertical section taken on the line 6--6 of Figure 1, particularly illustrating details of what might be called the control mechanism,

Figure '7 is a vertical section taken on the line 'I-l of Figure 2 illustrating other details of the control mechanism from` another position.

Figure 8 is a cross section taken on the line 8-8 of Figurev 7, particularly illustrating the combined sash slide and weather strip, and showing how the lock plunger of the lowerr sash interengages with the respective lock strip.

Figure 9 is a diagram of the electrical Wiring involved in the apparatus.

Figure l0 is a detail cross section taken on the line IIJ- I0 ofl Figure 1.

Figure 11 is a detail cross section taken on the line II-II of Figure 1.

The underlying purpose of the invention is to provide a simple inexpensive double hung window of simplified features, such as elimination of weights, cords, pulleys,-boX-frames and exposed locks, operable irrespective of size or weight of sash or location of the window by the mere turn of a pair of switches located at the window for local control or a corresponding pair of switches located at a distant point for remote control.

In addition to reducing the effort required in raising and lowering the sashes the sashes are automatically locked at any rest position by concealed locks inaccessible from outside.

Attention is directed to the drawings. I (Fig. 1) is a window frame of simple solid cross section welded at corners to form an inexpensive rectangular frame. On the inner face of frame I, grooves 33 are provided to receiveV sash slides and weather strips.

This window frame and its weather strips, as well as the meeting rail weather strips (later described), are the subject of a copending divisional application led by A. I-I. Tashjian and Dean H. Holden, February 7, 1935, Serial No. 5,473.

The sashes are preferably constructed of eX- truded metal of a cross section well represented in Figures 4, 8, 10 and l1, Figure 4 illustrating the meeting rails, I9, 20 of the two sashes, Figures 10 and l1 the respective top and bottom rails of the top and lower sashes, and Figure 8 side rails of sashes. In practice the various rails are mitred or coped and welded at the corners. Bores I5 in the side rails I6 receive in. tight t cylinders I I, I2, while bores I8 of the' meeting rails I0, 20 are closed by the tightly fitting closure metal members 28 (Fig. 4). `Bore I5 of the top rail 22 of the top sash It and bore I5 of the bottom rail 2l of the lower sash I3 are left open as shown (Figs, 10 and 11, or if desired may be closed with a strip of metal slid into grooves 24 merely as a closure. Figures 10 and 11 illustrate how the top and bottom rails 22, 2| may close upon weather stripping of a type presently described.

Circular grooves 25 of side rails and top rail upper sash and bottom rail lower sash engage over in snug t the cylindrical laterals 29 of a sash Weather strip 30 (Figs. 8, 10 and ll). These strips run full length both sides and across the head and sill of frame I. The strips 3|! ride over the metal backing 3|, the back ribs 34 of which are made to t into grooves 33 of frame I; Strips 30 and backing 3| are secured to the frame I by screws 32, of which one is shown in Figure 7. Strips 30 with their circular laterals 29 snugly t into corresponding grooves 25 of rails providing a very effective barrier against air infiltration between sash and frame. Strips 3l! and backing 3| at top and bottom act as Weather strips when both sash are in closed position while at sides act as sash-slide or track, as well as weather-stripping at the same time, thus eliminating the usual separate parting strip and sash-stop of conventional double hung window construction.

Parallel vertical beads 35 (Fig. 8) of backing 3| fit the cylindrical laterals 29 of strips 3l) loosely. The laterals are resilient, and the space therebetween and the beads 35 provides for any necessary relative movement when the sash is slid up and down, and at the same time insures a sufficiently snug friction fit in the circular grooves 25 to prevent the passage of air.

The cylindrical laterals 29 (Fig. 8) of the weather strip 30 together with the beads 35 of backing 3| at two sides of frame act as resilient and conformable tracks or slides for the sash side rail grooves 25.

As shown in Figure 8 the vertical grooves 24 of sash side rails I6 receive the vertical margins of lock strips 26 extending full height of sash. The lock strips are permanently secured to the sash rails I6, welded in place in the manufacture of the sash. The lock strips have a plurality of holes 2l (Figs. 3 and '7) for the reception of the point of a sash lock plunger.

For meeting rail weather-stripping and extending full width of each sash metallic membranes |39, |48 (Fig. 4) are provided carried by the meeting rails I9, 2l] of the lower and top sashes. The longitudinal sides of these membranes are bent at I4I, |42 so that each has a substantial U-shape. These bent edges are set in grooves |43, |44 arranged in confronting and parallel positions along the adjacent surfaces of the meeting rails.

Immediately to the inside of the bends I4| which jut out farthest from the respective meeting rail toward the other meeting rail there is a lip Ill-5. This assists in the support of the respective bend I4I, and inasmuch as it falls short of the place where the bend turns into the membrane proper there occurs a space which allows for any necessary flexing of the membrane toward the meeting rail. The membranes are ilexible, as just indicated. They stand on a bias to the meeting rails, and when the sashes are closed, as shown in Figure 4, the membranes come together and make a mutually conforming contact their entire length for a very effective weather-stripping at the meeting rails of the two sashes. The remote parts of the meeting rails have projections |45 which come as close to the opposite meeting rail as possible. These projections substantially enclose metallic membranes when the sashes are closed, and so add to the function of the membranes themselves in excluding draughts.

From the foregoing description of the construction of the window it will be noted that we have produced a double hung window of simpler assembly having eliminated weights, cords, pulleys, box-frames, and separate sash slides and sash stops, as a decided economy in cost of manuiacture.

To operate the sash a flexible tubing 16 (Figs. l and 6) is extended from a conventional compressed air tank located where wanted and connected to a control mechanism 52 mounted to side of frame I at about meeting rail height.

Under and at the two corners of the sill 3 (Fig. 2) of the window frame there are welded hollow blocks 4, 5 connected with the return air supply tubing TI from control mechanism 52. These blocks are connected by a common pipe E. Each block has connected to it a pair of tubular piston rods l, 8 (Fig. 2) extending into corresponding cylinders II and I2, thus providing a continuous open air raceway from air tubing 'Il to cylinders II and I2.

The pair of piston rods shown in Figure 2 are those at the right side of the window, looking at it from the inside. The pair of piston rods at the left are of identical form and function. Ihe piston rods are of substantially equal height. Each is open at the top, and adjacent to the opening they have heads herein shown as formed by flanges 9 (Figs. 5, 7) between which there is a wrapping of packing I0.

Sash cylinders II, I2 (Fig. 2) contain the piston heads 9, I 0. These cylinders are long enough to prevent the piston heads from coming out of their open ends when the respective lower and top sashes I3 and I4 are in their fully raised positions. The upper ends of the sash cylinders are closed, and the cylinders are Xedly fitted in bores I5 (Fig. 8) in the vertical side rails I6 of each of the sashes. A set screw I'I (Fig. 5), carried in part by one of the sash cylinders I I, projects into that cylinder far enough to strike the nether part of the respective piston head 9, I0 and so limit the up travel of the lower sash.

Each of the side strips 30 and backing 3| for the sashes I3 and I4 at the right of the window frame here shown, has a hole about midway of its height, in juxtaposition with a similar hole in frame I. The holes are designated 3E, 3'! (Fig. 2). These holes receive the exposed ends of center tubes 38 (Fig. 7) of lower and top sash l lock solenoids 39, 40 (Fig. 6). These tubes guide the respective lock plungers 4I, 42.

The plungers ride the holes adjacent to their free ends (Fig. '7). Each plunger has a point 43 to engage one of the lock strip holes 21 and so lock the respective sash in practically any position within its range of movement. The holes 2l are slightly over-size in comparison with the diameter of the point 43, enabling the sash to rest on the plunger point 43 holding said plunger from withdrawing, and also enabling a slight preliminary raising of the sash in order to take the weight of the sash from the lock plunger preparatory to the retraction of the plunger.

Each plunger has a pin 44 (Fig. 6) which extends through a felt Washer 45 and an iron stop 45 in the tube 38. The back end of each pin 44 is adapted to open a switch 41, 48, each switch comprising a fixed contact 49 and a movable spring contact 50, the latter being moved to the circuit-opening position when the respective solenoid is energized and its plunger is permitted to be drawn in upon the relief of the weight of the respective sash. i

The solenoids 3,9., 48, are contained by bores 5| in a block 52. `This block has` another bore 53 at right angles to the others. The block is secured to the frame by screws 54 (Fig. 7:) there `by supporting the block and covering the previously inserted solenoid's. The block 52 carries a suitably aliixed face plate 55, secured to the window frame by screws 56 (Figs. 1, 2 and 6). The block 52 and its carried parts are conveniently called the control mechanism.

A screw plug 51 (Fig. 6) holds an air valve solenoid 58 in the bore 53 (Fig. 7). The solenoid has a central tube 58 which slidably guides a plunger 66. The opposite ends of the plunger alternately abut felt washers 6|, 62 respectively against the plug 51 and an iron stop 63 of the tube 56. This stop is centrally bored at 64 to receive the hollow stem 65 of an air valve 66. This "valve controls the passage of air, it being understood that other pressure iluids might be employed in the operation of the window.

A hub 61, formed as part of the stem 65, abuts the stop 63 and so limits the position of the stem in the stop. The hub Ahas threads by which it is screwed into an air inlet chamber 68. The valve 66 is held engaged with a seat 69 in the center passage 18 of the stem 65 by a spring 1I. One end of the spring engages the valve, the other a stop in the passage. The Valve has a pin 12 which extends through a guide 13 into contact with the plunger 6|). The spring is strong enough `to push the plunger to the right (Fig. 6) after a deenergization of the solenoid 58, thus shutting off the air supply to sash cylinders Vthrough supply tubing 11.

Air nipples 14, 15 (Fig. 6) have the near ends of tubes 16, 11 connected to them by means of couplings 18. 16 is the inlet air tubing, admitting air to chamber 68 through a duct 19 from a conventional compressed air tank located elsewhere, while 11 is the air outlet tubing to sash cylinders. Upon energization of the solenoid 5B, the plunger 6|) is pulled to the left against pin 12 opening valve 66, allowing the inlet air to pass around the plunger 60 through a port 88 in the plug 51 (Fig. 6) through channel 8| and nipple 15 into tube 11 which in turn is connected tothe hollow block 4 (Fig. 1) by a coupling 82, and to hollow block 5 through tubing 6. When the foregoing passage of air occurs, all four cylinders and |2 are instantly filled with compressed air through the hollow rods 1, 8 attached to hollow blocks 4 and 5 respectively.

There are two electrical switches 83, 84 (Figs. 6 and '7) of identical constructio-n to control the passage of electrical current to the various solenoids for the operation of the sashes. The switch 83 is herein known as the top sash switch and the switch 84 as the lower sash switch. One of these switches is specifically described. The other bears the same reference numerals in the drawing with the exponent letter a for the purpose of distinction. The switch 83 is known to the trade as a jack switch. Its specific construction is not intended to be covered herein.

It has ashaft 85 (Fig. 6) with a turn button 86 on the outer end and an eccentric 81 on the inner end. The eccentric works between a pair of contactors 88, 89. One end of these is clamped in an insulating block in common with contacts 8|, 92, 83 and 84, while'the other ends are connected by an insulating bridge 95. The block 98 is carried by a bracket 86 (Fig. 2) which, in turn, is secured to the face plate 55 by suitable means 61 (Fig. l). y

Attention is directed to the electrical wiring diagram in Figure 9. The line 88 separates the part labeled Local control from the part labeled Remote control. The local control includes the switches 83, 84 which are mounted either directly on the window frame as shown, or near by in the room. The remote control goes to a more distant point. For the present set up there are four buses 69, |88, |8|, E82. The lrst two are power buses and they derive current from any suitable source |83. The others are respectively known as the lower Down bus and lower Up as labeled on the drawing.

A wire |85 commonly connects one end of the solenoids 38, 46 and 56 to the negative or return bus |56. A wire |85 connects the! other end of the solenoid 48 to the contact 82, a bridge |66 connecting the said wire to the contact 9|. A wire |81 connects the other end of the solenoid 38 to the contact 92, one branch |86 of that wire making connection with the contact 8| and another branch |09 making connection with a wire H8 which commonly connects the contact points Il l, ||2 of the respective down and up relays |13, |54. A wire ||5 connects the other end of solenoid 58 to the companion conr tact point H6 of the relay |18, one branch l| 1 of that wire making connection with the contact 94, another branch ||8 making connection with the contact 64a.

A wire ||9 connects the movable contact 58 of the switch 48 with the contact 93. A Wire |26 commonly connects the iixed contacts 49 of the switches 41, 48 and is ultimately connected with the branch l1. Ihe movable Contact 5|) of the switch 41 is connected by a wire |2| with the companion contact point |22 of the relay H3, a branch |23 of that wire making connection with the contact 93a. A wire |24 commonly connects the contactors 88, 88,8822, 89a with the positive bus 59.

The respective relays H3, ||4 include armatures |25, |26. They also have switches. |21, |23. The armatures and the coils of the: respective relays are connected to the return bus |88 by wires |29, |38. The other ends of the coils are connected with the movable points of the switches |21, |28, the fixed points of the latter being connected by wires |3|, |32 with the respective Down and Up buses |8|, |82. The remote control has Down .and Upf master switches |33, |34. Wires |35, |36 connect the positive bus 99 with the movable points of the respective switches. The xed points of the latter are connected with the down and up buses l, |62 by wires |31, |38.

The operation is readily understood. According to the showing in the drawings both sashes are closed. Assuming it to be desired to raise the lower sash |8 the procedure is as follows: Turn the button 86 of the lower sash switch 84 counterclockwise (arrow a, Fig. 9). The eccentric 81a depresses the pair of contactors 88a, 89a so that they engage the contacts 92, 84H Cur-v rent from the positive bus 68 iiows over wire |24, contactor 85, contact 64", wires |18, H5, solenoid 56, wire |84 to the return bus |88. The energization of the solenoid 58` (Fig. 6) moves the plunger 6|) toi the left, opening the valve 65 so that compressed air can ilow from the tube 16 to the tube 11 (Fig. 1) and so into both hollow blocks 4, 5 and each set of sash cylinders II, I2 by way of the tubular piston rods 1, 8, but up to this point in the description the lock plungers 4I, 42 (Fig. 6) of the lower and top sashes are still in the locking. position. Simultaneously with the foregoing ow of current there is also a passage of current from the positive bus 99 and wire 24 to the contactor 881'- (Fig. 9), contact 92a, wires I 92 and |01 to the lower sash solenoid 39, wire |84 and return bus |00.

While the energization of the solenoid 39 (Fig. 7) tends to withdraw the lock plunger 4I so as to free the lower sash i3, plunger 4| will not withdraw until the foregoing influx of air has just raised the lower sash from the point 43, so that when the point 43 is relieved of the weight of the sash the plunger 4| is free to be retracted. The air pressure then in the cylinders I, I2 causes the lower sash I3 to be raised. The top sash remains in locked position, as its lock solenoid is not energized, with the exception of the slight raising action allowed by the oversized hole 21 in which the respective lock plunger point fits at the time.

The retraction of the look plunger 4| (Fig. '7) causes the pin 44 to open the switch 41, but Without any effect this time in the electrical circuit. Later, when the solenoid 39 is de-energized, the movable contact 50, which is a spring, returns the plunger 4|f to its locking position. The lower sash i3 continues to rise as long as the button 88a is held to the counter-clockwise turn, and when it reaches the proper position the operator turns the button 898L back to the neutral position. This restores the switch 84 (Fig, 9) to its original position and cuts off electrical power from both solenoids 58, 39 deenergizing same. The lock plunger 4| returns to the locking position, as previously stated, its point 43 entering one of the holes 21 and so supporting and locking the lower sash in the then open position.

Upon desiring to lower the bottom sash the procedure is asV follows: Turn the button 85a of the switch 84 clockwise (arrow b, Fig. 9). The eccentric 81a raises the pair of contactors 88a, 89a so that they engage the contacts 9|a and 93e. Current then flows from the positive bus 99 over wire |24 to contactor 99a, Contact 93a, wires |23, I2| through the switch 48, wires |29, Ill', II5 to the solenoid 58, and wire |04 to the return bus |00.

The resulting energization of the solenoid 58 opens the valve 5B and admits air to the sash cylinders as before just enough to lift the lower sash from the point 43 (Fig. 7) as previously explained. Simultaneously with the foregoing passage of current there is also a flow from positive bus 99 and wire |24 to the contactor 88L (Fig. 9), contact 92a, wires |02 and |01 to the solenoid 39, and wire |04 to the return bus |00. The resulting energization of the solenoid 39 (Fig. '7) withdraws the then freed lock plunger 4I.

Simultaneously with the withdrawal of the lock plunger 4| its pin 44 presses back on the Contact 58 opening the switch 41 and automatically breaking the circuit through the solenoid 58. The resulting closure of the valve 66 (Fig. 6) cuts oir" the air supply to the lower sash cylinders. The switch 47 (Fig. '7) is, therefore, responsible for charging the lower sash cylinders I I with a measured quantity of air; enough to preliminarily lift the sash from the locking point 43 and then supplying an air cushion on which the sash will gently ride down as leakage of the fluid occurs past the piston pack ing I or through an auxiliary bleed hole (not shown) to atmosphere.

'I'he sash I3 continues to lower as long as the button 89@ is held to its clockwise turn. This is necessary to keep the solenoid 34 energized and the lock plunger 4| in the retracted position. As soon as the switch 84 is returned to neutral, the breaking of the circuit through the solenoid 39 causes the lock plunger 4| to move into the locking position by the spring 50 of switch 41 holding the lower sash locked in whatever position may be desired.

Upon desiring to lower the top sash I4 the procedure is as follows: Turn the button 86 of the top sash switch 83 clockwise (arrow c, Fig. 9). This raises the contactor pair 88, 89 so that the contacts 9|, 93are engaged. Current then iiows from the positive bus 99 over wire |24 to contactor 89, contact 93, wire 9, through switch 48, wires |20, ||1, to the solenoid 58 and wire |04 to the return bus |00. The resulting energization of the solenoid 58 (Fig. 6) draws the plunger G0 inward, opening valve 86 so that there is an air iiow into the sash cylinders.

Simultaneously with the foregoing there is also a current flow from bus 99 and wire |24 to contactor 88, contact 9|, wires |96, |05 to the solenoid 40 and wire |04 to the return bus |00. The resulting energization vof the solenoid 40 (Fig. 6), withdraws its plunger 42 from the locking position (compare with the plunger 4|, Fig; '7 the withdrawal of that plunger being permitted by the preliminary raising action of the top sash by the influx of air into its cylinders.

Following the withdrawal of the lock plunger 43, its stem 44 presses back on the movable spring contact 50 of the switch 48, automatically breaking the circuit of the air valve solenoid 58. The switch 48, is therefore, responsible for the introduction of a measured quantity of air to the cylinders of the top sash. The top sash gradually lowers on the diminishing air as the later leaks to atmosphere past the piston heads of the rods 8 (Fig. 2) or through the auxiliary bleed hole previously mentioned. Lowering continues as long as the button 86 is held to its clockwise turn. When this is restored to neutral the resulting de-energization of the solenoid 40 permits the respective spring contact 50 to move the lock plunger 42 to the locking position, holding the top sash locked wherever it may be caught.

Upon desiring to again raise the top sash the procedure is as follows: Turn the button 86 counter-clockwise (arrow d, Fig. 9). The contactor pair 88, 89 is depressed so that the current flowing from the positive bus 99 over wire |24 reaches wire |I1, II 5 by way of the contact 94, flows through the solenoid 58 and by wire |04 to the return bus |00. The resulting energization of the solenoid 58 (Fig. 6) opens the Valve 66 so that air is admitted to the sash cylinders. Simultaneously with the foregoing current also liows from bus 99 and wire |24 to the contactor 88, thence to contact 92, wire |05 to the solenoid 49 and wire |04 to the return bus |08. The relief of the weight of the sash I4 from the lock plunger 42 by the initial introduction of air enables the retraction of the lock plunger 42 upon the resulting energization of the solenoid 50.

The lower sash |4 continues to rise as long as the button 86' isheld to its counter-clockwise turn. When the 'switch ,83 is restored to the neutral position, the resulting breaking of the circuits of the solenoids 58, 40 cuts oi the flow of air to the sash cylinders and permits the lock plunger 42 to reassume its locking position. This holds the top sash locked in the desired position.

. As to the operation by` remote control it is desired to explain that the master switches |33, |34 (Fig. 9) are only for the operation vof the lower sash I3. There would only be a duplication of these switches and the addition of two buses such as |0I, |02 for the operation of the top sash I4 by remote control. Note that this master control by switches |33, |34 may `control as many windows as desired simultaneously.

Assuming it to be desired to raise the lower sash I3 by remote control, the procedure is as :follows: Close switches |21, |28. Ordinarily these switches remain open when the sashes are operated by local control only as described before. Switches |21, |28 are closed on all windows to be operated by master control. Those sashes which are not to operate have these switches left open. Close the upmaster switch |34. Current from the positive bus 99 iiows through the switch by way of wire |30, reaching the bus |02 by way of wire |38, whence it flows over wire |32, through switch |28, the coil of vthe up relay I|4 returning to the `return bus |00 by way of wire I3.

The energization of the coil attracts the armature |28 so that the contacts ||2, IIB are vbridged. A division of the current at the coil enters the armature, passes contact IIIi and ows over wire ||5 to the solenoid 58 and wire |04 to the return bus |00. The resulting energization of the solenoid 58 (Fig. 6) opens the air valve 06 as before.. The lower sash I3 is preliminarily lifted so that its lock plunger 4|' (Fig. '1) is freed of the weight.

Current also enters wire ||0 by way of contact II2, flowing over wires I 09, |01 to the solenoid 39, and by way of wire |04 to the return bus |00. The energization of the solenoid 39 (Fig. '1) retracts the lock plunger 4| so that the lower sash I3 is free to rise as long as the operator keeps the master switch |34 closed. Opening of the switch deenergizes the two solenoids so that the sash is stopped and locked.

Upon desiring to lower the sash I3 from the foregoing position by remote control, the procedure is as follows: Close the master switch I 33. Current ows from the positive bus 99 over wires |35, |31 to the bus |0I, over wire |3| past switch |21 and through the coil of the down relay ||3 from whence it returns to the negative bus |00 by way of wire |29. The energization of the coil attracts the armature |25 so that the contacts III, |22 are bridged. A division of the current enters wire |2| by way of contact |22, flowing through switch 41 and wires |20, I|1 and ||5 to the solenoid 58, then over wire |4 to the return bus` |00.

The resulting energization of the solenoid 58 admits air to the sash cylinders Current also enters wire ||0 by way of contact III, flowing over wires |09, |01 to the solenoid 39 and then by way of wire |84 to the .return bus |00. The energization of the solenoid 39 retracts the lock plunger 4| so that the sash I3 is free to lower on a cushion of air as described for local control.

The foregoing retraction of the lock plunger 4| opens the switch 41 so that the circuit of the solenoid 58 is broken. Only a measured quantity vof air enters the sash cylinders As this air cushion leaks past the piston heads the sash |3 gradually gravitates to the closed position. It can be stopped and locked in any desired position within its range of movement by opening the switch |33.

From what has been stated it must be clear that the raising of either sash is caused by the continuous application of air pressure as long as the respective switch 83, 84 is in the proper position. When the sash is raised as high as desired, the neutralization of the switch causes an automatic locking. The lowering of each sash is also caused by turning the respective switches 83, 84 to the proper position, but the switches 41, 48 fare involved in the lowering operation, and these serveto automatically cut off the air so that automatically only an amount of air is admitted to the sash cylinders in direct proportion to the sash Weights, rst for raising the sash oi `of the lock plunger, second to form a gradually leaking cushion on which the sash gravitates to the closed position. At this time the switches 41, 48 supersede the switches 84, 83.

We claim:- f

l. A sash, a lock plunger on which the sash is capable of being supported in a raised position, means into which a definite amount of pressure iiuid is admissible to preliminarily lift the sash from the lock plunger and then form a diminishing cushion by leakage from said means, and means to withdraw the lock plunger during the preliminary lifting of the sash.

2. A sash, a lock plunger to support the sash in a raised position, electrical means. which is energizable to retract the plunger, said means being insufliciently strong to retract said plunger while bearing the weight of the sash, and means into which a definite amount of pressure fluid is admissible to preliminarily lift the sash so that the plunger can be withdrawn, said means providing for the leakage of the fluid so that the sash can slowly lower on a diminishing uid cushion.

3. A sash, a lock plunger to support the sash in a raised position, electrical means adapted to be energized to withdraw said plunger, a pressure fluid valve, electrical means to open it and so enable the passage of iiuid from a pressure iiuid source, a source of current and a control by which to energize both electrical means from said source thereby opening the fluid valve but the electrical means of the lock plunger being insufficiently strong for its withdrawalv while supporting the weight of the sash, means into which the fluid released at the Valve is admissible to lift the sash from the lock plunger, the respective electrical means then operating to withdraw said plunger, and a switch then operated by the withdrawal of the plunger to de-energize the electrical means of the fluid valve and so cut oi the flow of fluid.

4. A sash, a lock plunger to support the sash in a raised position, electrical means by which to retract the plunger, a pressure fluid valve, electrical means by which to open the valve for the ow of iiuid from a pressure fluid source, a manual control by which to simultaneously energize both electrical means thereby to open the valve, the electrical means of the plunger being insufficiently strong to withdraw the plunger while supporting the Sash, means into which the sois fluid is admissible to raise the sash and so enable the electrical means of the plunger to withdraw it from a locking position, and means actuated by the withdrawing movement of the plunger to de-energize the electrical means of the Valve so as to close the valve and entrap a measured quantity of fiuid, the electrical means of the plunger remaining energized as long as the manual control is held.

5. A sash, a lock` plunger in position to hold 'the sash, means by which to apply the force of pressure fluid to the sash so as to lift it, means by which to pull on the lock plungen and cause its retraction in the initial lift of the sash at the application of pressure, and means automatically operated by the retracting movement of the plunger to cut off the pressure ud.

6. In a sash carrying a cylinder which contains a piston rod and piston fixed relatively to the sash, and means to admit pressure uid into the cylinder above the piston, a lock plunger on which the sash rests by gravity, means operating automatically upon the initial lift of the sash by the influx of iiuid to retract the plunger, and means acting by the retraction of the plunger to then cut off the influx of fluid to the cylinder, the resulting entrapped volume of uid in the cylinder being adapted to leak past the piston to lower the sash on a diminishing cushion.

'7. A sash, a lock plunger on which the sash rests by gravity, a lock strip carried by the sash and having a hole for the plunger, the hole being over-sized toprovide loose play, means to exercise a pull on the plunger in readiness for its withdrawal, and means to preliminarily lift the sash and thereby utilize the loose play for enabling the withdrawal of the plunger.

8. A pair of sashes each having at least one sash cylinder, hollow piston rods and pistons of substantially equal altitude and situated in the cylinders, a hollow block xed relatively to the sashes to which the rods are secured, a lock plunger for each sash and electrical retracting means for each plunger, a fluid valve and means by which it communicates with the block, electrical actuating means by which to open the valve so as to cause a fluid ow from a source of pressure uid and so introduce fluid into both cylinders, and a switch for each sash, the closing of either switch energizing the electrical means of the valve but only the electrical means of the respective lock plunger.

9. A sash, means in the sash by which to apply the force of pressure uid for its raising and lowering, a valve through which the fluid must ow for either purpose, electrical means to open the valve, a lock plunger to hold the sash either down or up, electrical means by which to retract the plunger, an automatic switch and plunger-operated means to open it on each retraction of the plunger, three circuits the first including the electrical means of the valve, the second including the electrical means of the lock plunger and the third including the automatic switch and the electrical means of the valve, and a manual switch movable into one position to energize the first and second circuits for a continuous application of pressure fluid to raise the sash and to retractl the plunger while the manual switch is held in the one position to energize the second and third circuits, the plunger-operated means automatically de-energizing the electrical means of the valve to cut 01T the pressure fluid for the lowering of the sash after a preliminary lift and the immediate retraction of the lock plunger.

ARMEN H. TASHJIAN. DEAN H. HOLDEN. 

